As long as you are rolling, steering usually isn't a big issue.
The brakes still work but you now have to provide all the power. Biggest issue is recovering from the surprise. You may be used to supplying 5-10lb of pressure to the brake pad and suddenly, you need to apply 50-100lb of pressure. If you are slow to adjust, it may be out of control before you have a chance to react.
One question: Before the engine died, did the battery light come on or some other warning? Normally, you would have some warning if the alternator quit entirely but before the engine cuts out.